Culturally we need to decide what our priorities are: do we sacrifice privacy and freedom for the appearance of safety or do we accept less promises of safety for more freedom and privacy.
You're right, we can't have it both ways.
I agree with you. I would rather the police have a principaled stand for freedom and privacy, and not murder people. Then if something big happens, as GP opined, we as a society need to not crucify them. The police are not and should not be a guarantee that bad things won't happen. We should hold them accountantable for what they do, not hold them responsible for preventing all evils.